What Is Perphenazine? Uses, Dosage, and What You Need to Know in 2026

What Is Perphenazine?

Perphenazine is a first-generation (typical) antipsychotic medication in the phenothiazine class, used primarily to treat schizophrenia and severe nausea and vomiting.

Originally marketed under the brand name Trilafon by Schering, Perphenazine has been available for decades and is now sold exclusively as a generic medication. It works by blocking dopamine receptors in the brain, which helps reduce psychotic symptoms like hallucinations, delusions, and disorganized thinking.

Perphenazine is not a controlled substance and does not require DEA scheduling. It is generally covered by most insurance plans and Medicare Part D as a Tier 1 or Tier 2 generic medication.

What Is Perphenazine Used For?

FDA-Approved Uses

• Schizophrenia — Perphenazine is approved to treat schizophrenia in adults. It helps manage positive symptoms such as hallucinations, delusions, and paranoia.
• Severe nausea and vomiting — When other anti-nausea medications fail, Perphenazine can be used to control severe nausea and vomiting in adults.

Off-Label Uses

Doctors sometimes prescribe Perphenazine off-label for:

• Bipolar disorder (manic episodes)
• Severe anxiety
• Agitated behavior
• Depression with psychotic features
• Hyperemesis gravidarum (severe pregnancy-related nausea)

Off-label use means the doctor is prescribing it for a condition not specifically listed in the FDA labeling. This is legal and common in medical practice when supported by clinical evidence.

How Is Perphenazine Taken?

Perphenazine comes as oral tablets in four strengths:

• 2 mg
• 4 mg
• 8 mg
• 16 mg

For schizophrenia: The typical dose range is 4 mg to 64 mg per day, divided into two or three doses. Most patients are maintained on 8 to 24 mg per day.

For severe nausea and vomiting: The usual dose is 8 to 16 mg per day in divided doses.

Perphenazine can be taken with or without food. Your doctor will typically start you at a lower dose and increase gradually based on your response and tolerance.

Important: Do not stop taking Perphenazine suddenly. Abrupt discontinuation can cause withdrawal symptoms including nausea, vomiting, dizziness, and tremors. Always work with your doctor to taper off gradually.

Who Should Not Take Perphenazine?

Perphenazine is not safe for everyone. You should not take Perphenazine if you have:

• A known allergy to Perphenazine or other phenothiazine medications
• Severe CNS depression (from alcohol, barbiturates, opioids, or other depressants)
• Comatose states
• Blood dyscrasias or bone marrow depression
• Pre-existing liver damage

Boxed warning: Perphenazine carries an FDA boxed warning about increased risk of death in elderly patients with dementia-related psychosis. It should not be used to treat behavioral problems in elderly dementia patients.

Use with caution in patients with:

• Cardiovascular disease
• Seizure disorders
• Parkinson's disease
• Liver impairment

For a detailed list of medications that interact with Perphenazine, see our drug interactions guide.

How Much Does Perphenazine Cost?

Because Perphenazine is available only as a generic, it's relatively affordable compared to many newer antipsychotics:

• Retail price (no insurance): $100 to $130 for a 30-day supply
• With discount coupons: As low as $19 to $23 using GoodRx, SingleCare, or RxSaver
• With insurance: Typically a low copay (Tier 1 or Tier 2). Prior authorization is usually not required.

For more ways to save, check out our guide on coupons, discounts, and patient assistance programs for Perphenazine.

If you're having trouble finding Perphenazine at your pharmacy, Medfinder can help you check which pharmacies near you have it in stock.

What Are the Side Effects?

Like all antipsychotics, Perphenazine can cause side effects. Common ones include drowsiness, dizziness, dry mouth, constipation, blurred vision, and weight gain. Serious risks include tardive dyskinesia, neuroleptic malignant syndrome, and extrapyramidal symptoms.

For a complete breakdown, see our detailed article on Perphenazine side effects.

Final Thoughts

Perphenazine is a well-established antipsychotic that remains an effective option for schizophrenia and severe nausea. It's affordable as a generic, covered by most insurance plans, and doesn't require prior authorization in most cases.

If you're new to Perphenazine or considering it as a treatment option, talk to your doctor about whether it's right for you. And if you need help finding it at a pharmacy, Medfinder makes it easy to check stock in your area.